Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	$ (171,096)
Investment securities losses, net	(197)	$ 0
HTM investment securities, net, at amortized cost(a)	(2,060)	(2,267)
Unrealized Gain (Loss) on Cash Flow Hedging Instruments	(19,461)	13,763
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, before Tax	4,823	1,262
Personnel expense	(119,395)	(116,420)
Net other comprehensive (loss) during period	(38,785)	39,211
Ending Balance	(209,881)
AFS Investment Securities
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	(148,641)	(233,192)
Other comprehensive (loss) before reclassifications	(29,889)	36,478
Investment securities losses, net	197
HTM investment securities, net, at amortized cost(a)	2,060	2,267
Unrealized Gain (Loss) on Cash Flow Hedging Instruments	0	0
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, before Tax	0	0
Personnel expense	0	0
Other expense	0	0
Income tax benefit (expense)	6,885	(9,892)
Net other comprehensive (loss) during period	(20,746)	28,853
Ending Balance	(169,388)	(204,339)
Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	3,080	3,360
Other comprehensive (loss) before reclassifications	0	0
Investment securities losses, net	0
HTM investment securities, net, at amortized cost(a)	0	0
Unrealized Gain (Loss) on Cash Flow Hedging Instruments	(19,461)	13,763
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, before Tax	4,823	1,262
Personnel expense	0	0
Other expense	0	0
Income tax benefit (expense)	(1,688)	(4,694)
Net other comprehensive (loss) during period	(16,326)	10,331
Ending Balance	(13,246)	13,691
Defined Benefit Pension and Postretirement Obligations
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	(25,535)	(42,968)
Other comprehensive (loss) before reclassifications	0	0
Investment securities losses, net	0
HTM investment securities, net, at amortized cost(a)	0	0
Unrealized Gain (Loss) on Cash Flow Hedging Instruments	0	0
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, before Tax	0	0
Personnel expense	(72)	(81)
Other expense	(7)	30
Income tax benefit (expense)	(1,633)	79
Net other comprehensive (loss) during period	(1,712)	27
Ending Balance	(27,247)	(42,940)
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	(171,096)	(272,799)
Other comprehensive (loss) before reclassifications	(29,889)	36,478
Investment securities losses, net	197
HTM investment securities, net, at amortized cost(a)	2,060	2,267
Unrealized Gain (Loss) on Cash Flow Hedging Instruments	(19,461)	13,763
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, before Tax	4,823	1,262
Personnel expense	(72)	(81)
Other expense	(7)	30
Income tax benefit (expense)	3,564	(14,507)
Net other comprehensive (loss) during period	(38,785)	39,211
Ending Balance	$ (209,881)	$ (233,588)